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Different gain traces at RX interfaces

Arash Jafari

Wed, Jul 22, 2020 8:37 AM

Hello All,

My instrument (USRP X310) has 2 equivalent UBX-160 daughter boards.

RX Dboard: B| | | ID: UBX-160 v2 (0x007e)| | | Serial:
31D5B02*

I applied an equivalent external stimulus at both RX interfaces.
but the same stimulus signal at RX1 and RX2 interfaces results in an 18 dB
difference in relative gain trace!!!!!!
In attachment please find the relative gain trace.
Does anybody know what is wrong with the board?
Thank you in advance!

--
Dipl.-Ing. Arash Jafari

Phone: +43 650 844 3617
E-mail: arash.jafari.telecom@gmail.com

Hello All, My instrument (USRP X310) has 2 equivalent UBX-160 daughter boards. *| | | RX Dboard: A| | | ID: UBX-160 v2 (0x007e)| | | Serial: 31D5AC* * RX Dboard: B| | | ID: UBX-160 v2 (0x007e)| | | Serial: 31D5B02* I applied an equivalent external stimulus at both RX interfaces. but the same stimulus signal at RX1 and RX2 interfaces results in an 18 dB difference in relative gain trace!!!!!! In attachment please find the relative gain trace. Does anybody know what is wrong with the board? Thank you in advance! -- Dipl.-Ing. Arash Jafari Phone: +43 650 844 3617 E-mail: arash.jafari.telecom@gmail.com

Marcus D. Leech

Wed, Jul 22, 2020 5:07 PM

On 07/22/2020 04:37 AM, Arash Jafari via USRP-users wrote:

Hello All,

My instrument (USRP X310) has 2 equivalent UBX-160 daughter boards.

RX Dboard: B
| | | ID: UBX-160 v2 (0x007e)
| | | Serial: 31D5B02*

I applied an equivalent external stimulus at both RX interfaces.
but the same stimulus signal at RX1 and RX2 interfaces results in an
18 dB difference in relative gain trace!!!!!!
In attachment please find the relative gain trace.
Does anybody know what is wrong with the board?
Thank you in advance!
*
*
*
*

Dipl.-Ing. Arash Jafari

Phone: +43 650 844 3617
E-mail: arash.jafari.telecom@gmail.com
mailto:arash.jafari.telecom@gmail.com

How are these interfaces being driven? Hard-wired? Antenna? What is
the magnitude of the stimulus signal?

Are you sure you are plugged in to the right connectors on the front
panel? Is the gain being set to the same thing on both interfaces?

On 07/22/2020 04:37 AM, Arash Jafari via USRP-users wrote: > Hello All, > > My instrument (USRP X310) has 2 equivalent UBX-160 daughter boards. > > > *| | | RX Dboard: A > | | | ID: UBX-160 v2 (0x007e) > | | | Serial: 31D5AC* > * > * > * RX Dboard: B > | | | ID: UBX-160 v2 (0x007e) > | | | Serial: 31D5B02* > * > * > I applied an equivalent external stimulus at both RX interfaces. > but the same stimulus signal at RX1 and RX2 interfaces results in an > 18 dB difference in relative gain trace!!!!!! > In attachment please find the relative gain trace. > Does anybody know what is wrong with the board? > Thank you in advance! > * > * > * > * > -- > Dipl.-Ing. Arash Jafari > > Phone: +43 650 844 3617 > E-mail: arash.jafari.telecom@gmail.com > <mailto:arash.jafari.telecom@gmail.com> > How are these interfaces being driven? Hard-wired? Antenna? What is the magnitude of the stimulus signal? Are you sure you are plugged in to the right connectors on the front panel? Is the gain being set to the same thing on both interfaces?